/Engine/Plugins/Importers/USDImporter/Source/USDTests/Public/USDTestsBlueprintLibrary.h
Internally opens the provided stage and sets it on the stage actor via C++
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Counts") static void SetUsdStageCpp ( [AUsdStageActor](API\Plugins\USDStage\AUsdStageActor) * StageActor, const [FString](API\Runtime\Core\Containers\FString) & NewStageRootLayer )